Obligation and Necessity
When deciding which modal to use to express obligation and necessity, there are a number of challenges which you will face. One thing which poses a problem for students is the fact that the meaning of a modal can change depending on time and whether a sentence is in the positive or negative.
The following activity is designed to test your current understanding and teach you some of the rules you may not be aware of at C1 level. Have a go at answering the different questions. Where feedback is provided, it’s important that you read it even if you get the correct answer as there may well be some rules which you have not come across before.
Now you’ve had a good look at the rules, try the following exercise by rewriting the second sentence so it has the same meaning as the first. You may need to use a modal or another way of expressing obligation and necessity. There may be more than one possible answer.
To finish off, let’s take a closer look at have to. Using the rules you’ve learnt on this page and your knowledge of tenses, choose a correct option from the dropdown menu for each sentence. Again, there may be more than one option.